ABSTRACT The Biostatistics Core will provide high quality, efficient, integrated collaboration in and support of the proposed Center on Deep Brain Stimulation (DBS) for Parkinson's Disease (PD). The overall theme of the Center is to develop novel, circuit based deep brain stimulation (DBS) therapies for Parkinson's disease (PD). As a foundation for all three proposed projects in support of this theme, this Core will provide: personnel with the appropriate breadth and depth of expertise; services in study design, study logistics planning and implementation, data management and quality control, and statistical analysis; data integration with and transfer to the NIH/NINDS Parkinson's Disease Biomarker Program Data Management Resource; career development related to statistical concepts for clinical and basic scientists in the Center; participation in outreach and dissemination activities; and other resources as needed. We will interact closely and extensively with the Administrative Core, the Clinical Core, and the Imaging Core on scientific and management services for each project as it is carried out; on the seamless integration of all cores' services with each other to best support the projects; on the prioritization of this Core's work across the needs of the projects; on the ongoing career development of Center investigators; and on supporting future research and funding opportunities on DBS strategies in PD which are motivated by this proposed Center. This Core's personnel will participate with project teams before study initiation, during study execution, through study dissemination, and as part of novel cross-project initiatives that will integrate the projects to provide innovative insight into the pathophysiological basis of motor signs in PD. This Core's continuity of involvement will provide a common connection among the projects and continuous interaction with the other cores, spanning the entire proposed period. Lastly, we will provide resources for additional exploratory analyses that come to light as the research progresses, taking full advantage of the Center's careful data collection and management, thereby also facilitating the development of innovative hypotheses for future research.